NOTICE

Forums are temporarily disabled while we are working on a new login procedure.

When migrating the old forums over to our new forums we were unable to retain the identity of the authors, so the old posts will show up as "anonymous". All NEW posts will show up credited to their authors. So please participate and share knowledge just as you have in the past.

You must log in if you are an existing user or register if you are a new user in order to contribute to the discussions.

Discussion Forums - The Hendrix Group
HomeHomeDiscussionsDiscussionsMaterial Select...Material Select...Cold forming of Austenitic stainless steelCold forming of Austenitic stainless steel
Previous
 
Next
New Post
12/5/2008 9:00 AM
 
Hi dears I have a question about cold forming of austenitic stainless steel. If A.S.S. be in solution annealed condition, how much cold forming maybe result outgo from this condition (because of generation low-carbon martensite due to cold forming)? best reagrd
 
New Post
12/5/2008 9:00 AM
 
Micro eng It depends. If it is Aus S.S - 304/316 grade, cold forming upto 10% will not work harden to a great extent. Piping code allows this so long as it is not meant for environment which makes the Aus S.S susceptible for SCC. For example: Exchanger tubes - U bends - can be cold formed as per piping code easily to 10% and with 10% work hardened tube you can use safely in corrosive environment likely to produce SCC without much adverse problem of failure. If it is above 10%, work hardening of Aus S.S material, the work hardened stress and corrosive environment factor (concentration of corrodent, service temperature, agitation, restrictions in liquid or gas flow etc) likely to produce SCC effects have to be weighed before considering whether you need solution annealing and quenching of Aus S.S. The same holds good for your query on MR-0103 - on need for solution annealing and quenching of a work hardened Aus S.S in sour or sweet service in oil& gas or refining or petro chemical services. So long as the weld hardness is below 20 HRc( < 200 BHN) a work hardened Aus .S.S can be used in sour or sweet service in oil & gas but meeting to MR- 0103 without great risk of SCC. Hope this helps C.V.Srinivasan Nishi Engineers Pvt. Ltd India Dec 06, 2008 E-mail: nishi@vsnl.com >Hi dears >I have a question about cold forming of austenitic stainless >steel. >If A.S.S. be in solution annealed condition, how much cold >forming maybe result outgo from this condition (because of >generation low-carbon martensite due to cold forming)? >best reagrd
 
New Post
12/6/2008 9:00 AM
 
Added to Mr.Srinivasan reply for Aus.SS hardness limitation is more than 200BHN. Regards,
 
New Post
12/23/2008 9:00 AM
 
From the data I have seen for 304 ss, at room temperature you need to achieve about 20% true strain before martensite transformation can be detected. This information is right out of the "Handbook of Stainless Steels" by Peckner and Bernstein. Now regarding useability, this is a different matter because I would be more concerned with residual tensiel stress and increased susceptibility to carbide precipitation and to stress corrosion cracking with even 10% true strain, despite no detectable martensite transformation product.
 
New Post
12/23/2008 9:00 AM
 
Microeng It is true that 20% work hardening will give rise to martensite transformation (to some extent) in SS materials at RT. Hand books give general effect information for guidance purposes. From effect of SCC, you have to consider the specific corrodent (for example : chlorides, sulphides, alkali or other effect of contaminants in corroding medium, temperature, concentration, agitation, velocity, welding and residual stresses in HAZ or parent material etc and then consider the effect of cold working or hot working strain of --% strain on SS materials). With specific corrodent and the above likely factors taken into account one has to look the effect of --% of strain (whether cold worked or hot worked or welding and residual stresses due to welding) before raising a question or getting worried on a general assumption of --% strain would be harmful from effect of SCC in SS materials. Your apprehension on the effect of SCC on SS 304/316 with 10% work hardened strain and the question or doubt raised is too general to answer at this stage. In fact you will be surprised that residual tensile stresses due to welding in HAZ or parent material will be much higher in some cases (due to care in welding - weld design, welding inter pass and post care practices) may be as high as yield strength in some cases (compared to the 10% strain you are considering will harm SS) that even small quantity of chloride in ppm level will promote SCC at RT Hope this clarifies your point raised C.V.Srinivasan Nishi Engineers pvt ltd India Dec 24, 2008 E-mail: nishi@vsnl.com >From the data I have seen for 304 ss, at room temperature >you need to achieve about 20% true strain before martensite >transformation can be detected. This information is right >out of the "Handbook of Stainless Steels" by Peckner and >Bernstein. > >Now regarding useability, this is a different matter because >I would be more concerned with residual tensiel stress and >increased susceptibility to carbide precipitation and to >stress corrosion cracking with even 10% true strain, despite >no detectable martensite transformation product.
 
Previous
 
Next
HomeHomeDiscussionsDiscussionsMaterial Select...Material Select...Cold forming of Austenitic stainless steelCold forming of Austenitic stainless steel


  

News

With a little delay, our Calculation of Ammonium Salt Deposition Temperatures...read more
Our sulfidic corrosion calculators are now available at hghouston.com/calcula...read more

Stay Current

Sign up for our quarterly newsletter

covering updates on corrosion

Sign Up